Is the RPi gateway capable of local speech recognition that can compete with Siri, Alexa, Google? That seems unlikely, unless it has a dedicated processor for that purpose.
Personally, I'm not one for using Pis as computers, because I have always running computers at home anyways. I'm quite confident my computer can handle adequate voice recognition, though most companies today have avoided developing solutions that run locally.
EDIT: Fixed typo
We were doing local speech recognition and full voice dictation back in the 90's through products like this (https://en.wikipedia.org/wiki/Dragon_NaturallySpeaking). Back then your typical computer had a 100Mhz processor and would be lucky to have 32MB of RAM. So yes, with 20 years of progress the much more powerful rasberry pi should be able to handle it just fine.
Make no mistake, siri, alexa and google are spyware, they send your information to themselves because they want to, not because they have to.
I have worked with several speech recognition softwares, and the ones which can run on a low-powered device in real-time today are not the ones reaching 95% accuracy.
Dragon was trained for me, google is trained for some mythical "everyone".
> These systems typically use deep convolutional neural network (CNN) architectures ... driving the word error rate on the benchmark Switchboard corpus down from its mid-2000s plateau of around 15% to well below 10%.
If nothing else, you could probably just hook up the AIY voice kit to it. If the software for the AIY voice kit runs on that OS image, it's pretty trivial to do it. There're multiple tutorials about how to make that happen.